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Building a Better Barn for Corporate Aircraft

There have been a lot of changes in hangar design and development over the past few years.


September 28, 2007
By Rob Seaman

Topics

295-barn

Many have always seen a hangar as just a big box to stuff airplanes
into. The truth is that a great deal has changed in hangar design and
development in recent years – and a box it is not! Some of these
changes have come through need or experience, but even bigger changes
have been brought on by municipal, airport and national safety
standards. The bottom line: building a hangar requires the right
combination of planning and operator input to result in something that
will serve all interests for many years – especially with the cost of
developing such a facility today.

If
you operate a corporate aircraft in Canada you need a shelter for it.
And at a time when deliveries of new turbine-powered aircraft have hit
record highs, as they did during the first half of this year, more and
more aircraft owner/operators are seeking a place to call home. Demand
for hangar space on average far exceeds available and/or affordable
space at most airports. But as FBOs have been continually squeezed
financially, the revenues to support such a project are limited. To
build a hangar today means having virtually pre-sold the space before a
shovel hits the ground.

Hangar management and design for
corporate and private aviation in Canada took a significant turn in the
early 1990s when Skyservice first acquired the old Worldways hanger on
the south side of Toronto’s Pearson International Airport. The personal
vision of company head Russ Payson played a big role in revamping what
was basically a utility airline hangar and transforming it into a
first-rate corporate support centre. The most noticeable upgrade was
the addition of insulation to the walls and ceiling and a bright white
paint finish applied to all surfaces. This was the first working hangar
of its kind in Canada. Skyservice contracted a specialty firm to apply
its unique heavy-duty, epoxy-based finish to the basic concrete floors.
The end product was stunning – yet held a practical focus too. White
floors make it easier to find items dropped during maintenance or
flight preparation. They also encourage people to keep their workspace
neat and clean. And the finish is such that it resists spills and
fluids permeating into the concrete.

The bright surface of an
all white hangar better reflects light and enables the operator to
light the space with fewer lamps. When older hangars are refitted, half
of the existing lights can often be turned off for a significant cost
saving. The white hangar also improves human factors. People working in
bright, airy spaces are less susceptible to environment-driven mental
stress.

Gordon Williams a consultant in hangar development and
project management based in Prince Albert, Saskatchewan says the
biggest difference in hangar design and construction today is the use
of clear-span technology. This eliminates centre support columns to
provide wide, open and impressive areas. As wingspans and tail heights
of corporate and commercial aircraft continue to grow, most recently
designed hangars can accommodate a Global Express, BBJ or GV – and
still have room for a gaggle of Citations, Falcons, Lears and King Airs.

Early
hangar heating – a necessity in Canada – was based on systems that were
so inefficient, and the hangars so poorly insulated, that to work on
aircraft in the dead of winter frequently meant wearing layers of
clothing under coveralls. One of the early changes was the use of
under-floor hot-water systems. These tended to overheat the lower
hangar area while providing precious little heat to higher-level
working areas. And their maintenance cost was high. A line break or
leak meant digging up the entire floor to fix it. Forced-air natural
gas systems also had limitations, such as the size required to
effectively get the warm air down to the floor area when the units are
placed high above wings.

Today, the most effective heating
systems are based on radiant units, wall- or ceilingmounted. These
systems provide consistent heat – especially when opening a hangar door
in February! Radiant heaters are engineered for efficiency and can be
serviced with relative ease. And because they can be mounted at or near
the roofline, they can be positioned properly to avoid interference
with aircraft tail surfaces. Another important consideration in
Williams’ view is the need for low-intensity infrared tubes – not
highintensity heaters. The latter will burn paint if too close.
Low-intensity can be within 10 feet of surfaces and not cause damage.
Also, highintensity units can damage newer carbon fibre and composite
flight controls. The other advantage of infrared is that it gently
heats the concrete floor, creating a ‘heat sink’ and so holding the
heat when doors are opened for a short time. This results in much
quicker temperature recovery when doors have closed again.

Hangar
fire-suppression systems have come a long way in recent years and
regulations have changed. Municipalities and local airport authorities
have a great deal to say about hangar fire-prevention systems employed
today. Long gone are the days of simple water-based ceiling sprinklers.
The fire system today takes into consideration chemical, electrical,
aviationfuel and structural fires. While sprinkler and standpipe
systems have been utilized over the last number of years, foam systems
are the recent trend showing an increasing desire for a total deluge
process. Once the system is activated, the entire hangar is flooded
with massive quantities of water drawn from a designated on-site
reservoir, and foam. The speed and force with which such systems deploy
in larger hangars is frightening. However the intent is to choke out a
fire while it is still localized and contained.

Another point
that Williams always makes to his clients is the design of walkways,
emergency stations and material storage. In the old days, we could
stack things to the rafters, keep boats and cars in there too and not
worry. That has changed and modern hangar engineers incorporate current
thinking into their layout. First, a clear walkway of no less than six
feet in width should be established around the perimeter of the
facility. While this means lost revenue potential for the hangar
keeper, it does have significant reasoning behind it. This space has to
be clear and identified by painted lines on the floor. Aircraft tails
must not be overlapped into this area nor toolboxes and O2 bottles that
need to be stored there. It must be maintained as a clear passage for
emergency and general hangar passage rights.

Modern hangars must
also include eye and chemical wash stations – and this may necessitate
running water to the identified area. While some of the aftermarket
eyewash units simply bolt to the wall – and therefore do not impede the
passageway – full wash stations need a drain and shower feed and must
be of sufficient size to allow an average adult to stand in the area
and become totally soaked in a mater of seconds. Depending upon the
size of the hangar, multiple stations may be required.

You
cannot get away from having things stacked at the side of the hangar.
The best solution is to create and designate an area for this, and then
allow your emergency path to flow around it. Cages for lockup
goods/quarantine and designated areas to roll jacks, stands and
toolboxes into usually fall into this sort of thinking. As with all
such things Williams advises that you plan it into the design at the
beginning and then the finished product will be that much better.

The
same can be said for electrical conduits and panels that find their way
into and around the hangar walls. One of the great challenges during
routine hangar operations is trying to discover or understand what is
what with this sort of thing. Once again – a bit of planning and lots
of labelling will make the job easier for others. Clearly identify all
electrical conduits not only on the panel but as they are affixed and
travel along the wall. People will then be able to understand what is
where. In an emergency, such identification can be the difference
between having a full-blown disaster or not.

Many new hangars
have a ‘power pit’ in the centre line – or a number of them. With
clear-span hangars, there are no walls into which you can place the air
and power outlets. This causes unacceptably long runs of air lines or
extension cords running across the hangar floor. The solution is ‘power
stations’, with air and power outlets for everything from a work light
to a GPU. Outlets are wheeled into position over the ‘pit’ and hooked
up after the aircraft are positioned in the hangar. It is neat, clean
and effective.

Birds in hangars have long raised the ire of
aircraft owners. In older units, it was easy for them to hide in the
rafters. Modern whitefinished facilities make it easier to spot these
feathered bombers before they take up residence. The systems now
employed to battle the damage their feces cause to an aircraft finish
is well advanced beyond the old norm of poisons or pellet riffles. The
first line of defence comes in the design of the facility, and savvy
designers will look to avoid creating entry points or areas that are
dead space and accordingly look attractive for nesting. On the
technology front, the solutions range from textures and finishes that
discourage birds landing on a surface to ultrasonicfrequency emitters.

Doors
and the tracks they move on are another quirky area of hangar
development. Recent innovations have ranged from high-density,
reinforced roll-up doors made of synthetic fibres, to sectioned,
all-metal or aluminum units that open up and are hinged in the middle
to vertical sections, offset to link with each other as they slide
across to form a solid unit. In the case of all modern applications,
the doors require motors to move them. These require maintenance and
care or else they will let you down just when need them most – in the
middle of a gale or snowstorm. Many operators whose doors are
constantly being opened and closed keep a spare drive motor on hand as
back-up. This is especially important with upwardopening doors. On the
vertical units, a broken motor usually means a lot of pushing and
pulling until a ramp tug can be brought in to push or pull for you.

The
track component of hangar doors is an even more sensitive area. An
inset or near-level track collects debris and in winter snow and ice.
Most hangar designs today have moved away from raised tracks due to the
pressure they can place on high-pressurefilled aircraft tires being
bounced over them. So with a recessed or flush fit, it becomes even
more important to perform frequent track cleaning and maintenance.

To
help with this, most door designs have the units set well enough back
of the actual front of the hangar so as to provide some element of
shelter/overhang from the elements. This helps reduce the buildup of
foreign matter in the track and allows the doors free movement. One
caution that Williams adds is to ensure that with track doors, a good
drainage path for water is present. Many doors freeze up with rain or
melt off. Most important, Williams says, is that hangar doors in Canada
should never face north or northwest, as that is where the wind comes
from! One final consideration unique to Canada is heating the door
tracks with replaceable heaters. The reason to specify replaceable
units is simple: after five years, when the old ones burn out you don’t
want to be jack hammering out the concrete. Don’t live in hope that
they will not burn out – because one day they will.

How much
does all this cost? Averio Constructors of Dorchester, Ontario, is
experienced in hangar design and construction with two widebody hangars
at Pearson and similar projects in Europe and elsewhere. Taking a
55,000- square-foot hangar as the design criteria (that would be enough
space to put in one B737 and a hand full of Citations and Learjets plus
all the support equipment or one A330-200 or one B777), Gil Camarinha,
director of operations, advises to budget roughly US$3.8 million. That
will get you a prefabricated/pre-engineered building built in Canada
and installed on your site.

For that sort of money you can go
from an undeveloped piece of land and get one hangar door, side walls
fully clad with metal siding, a standpipe fire-protection system, the
whole building insulated with fibreglass and designed to the area
maximum wind and seismic loads. The floor needs to be 12" thick for the
777 or the A330-200, 8" thick for the tug areas and everywhere else.
Door width should be clear of the maximum wing tip by at least eight
feet and ceiling height/clearance will be sufficient to clear the tail
height. Design today will also take into consideration care when
turning an aircraft inside the hangar.

Camarinha says that if
your local airport authority insists on a fire deluge system, the
estimate for foam deluge on a hangar of this size can add around US$1.7
million. If you want to add office/shop space to the sides and back,
the design and construction will run any where between $65 and $105 per
square foot. The last thing that many request is an extra or rear
hangar door. Averio advises adding another $400,000 to the budget for a
really wide door. And one final note – none of this includes the cost
to complete ramp and apron areas that will be designed and developed to
withstand the weight of the aircraft or the set-up and installation for
external lighting and security fencing.

So now you know what it
costs and what you need. Are you ready to build your dream hangar?
Well, just wait until you talk to the airport authority about land –
but that is another story.